Anyone over the age of 17½ years can attend a folk high school (the Youth folk high schools admit young people between 16 and 19 years of age) – no matter their educational background.
Folk high school is for everybody
The courses are meant to broaden general, social and democratic competences. This means that you can meet young people at 18 who just finished high school; students at the universities taking a year off, 25-year-olds who still do not know what to do with their lives, adults with an education exploring new sides of themselves etc.
Please be advised that in order to attend a Danish folk high school you must be able to participate in the education provided. This means that you have to be able to understand and speak the language the course is conducted in, which most likely would be Danish or English.